Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds some behavioral context beyond annotations: it explicitly says 'read-only' (matching readOnlyHint) and describes bulk support (accepting ids, product_ids). However, it does not disclose details like pagination behavior, rate limits, or the meaning of the 'Flattened action: get' note, which could confuse the agent. The annotations already declare safety (readOnlyHint, idempotentHint, destructiveHint=false), so the description's added value is limited.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise in length but dense and packed into a single paragraph with heavy use of parentheses and lists. It is not well-structured; the list of actions and filters is crammed together, and the '[Flattened action: get]' note is unexplained. Some information could be reorganized for clarity, but it is not excessively verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (15 params, multiple actions, no output schema), the description is insufficient. It does not explain what each action returns, does not clarify ambiguous parameters, and does not provide any examples or usage scenarios. The lack of differentiation from sibling tools and the unexplained '[Flattened action: get]' further reduce completeness. This tool would be difficult for an agent to use correctly without additional context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 15 parameters and 0% schema description coverage, the description is the only source of parameter meaning. It maps filters to actions (e.g., search uses subscription_status, product_id, contact_email, etc.) and mentions bulk support for ids/product_ids. This provides some context but leaves many details unclear (e.g., date formats for started_at_ini/end, allowed values for subscription_status, how cursor works). The description does not fully compensate for the lack of schema descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states the tool is for reading Guru subscriptions ('Assinaturas no Guru (leitura)') and lists multiple actions (search, get, activities, etc.), so the overall purpose is clear. However, it is ambiguous which action to use for a given request, and it overlaps with dedicated sibling tools (e.g., guru_subscriptions_search, guru_subscriptions_invoice), making it unclear how this tool differs. The '[Flattened action: get]' hint is cryptic and does not resolve the ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit guidance on when to use this tool versus alternatives. It lists actions and filters but does not explain when to prefer this tool over the more specific sibling tools (e.g., guru_subscriptions_search for searching, guru_subscriptions_invoice for invoices). The note about bulk support is the only practical hint, but it lacks a clear 'use this when...' directive.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.