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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds domain context ('people linked to CRM accounts') and the optional filter behavior, but no additional behavioral caveats beyond what annotations and schema imply.

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 a single, front-loaded sentence with no filler. Every phrase contributes meaning: 'List contacts', the parenthetical clarification, and the optional filter note.

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?

For a simple list operation with full schema coverage, clear annotations, and an output schema, the description sufficiently covers the tool's purpose and options. It doesn't need to explain return values or pagination since the output schema and limit parameter description handle those.

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?

The schema provides descriptions for all three parameters (limit, search, accountId) at 100% coverage. The description only names the account/search filters without adding syntax or format details, so it meets the baseline but doesn't elevate it.

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 uses a specific verb ('List') with a specific resource ('contacts') and clarifies the domain as 'people linked to CRM accounts'. It also mentions optional filters by account or search, making it distinct from single-contact retrieval (get_contact) or contact creation (create_contact).

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?

The description clearly implies when to use this tool (listing contacts with optional filters), but it does not explicitly state when not to use it or compare it to sibling tools like get_contact or search_crm. It gives clear context without exclusions.

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