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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It mentions the owner-only restriction, which is helpful, but omits critical details such as whether the update is partial or full, what side effects occur beyond the group cannibalisation note (which appears only in the schema, not the description), what the response looks like, and whether the operation is reversible. This is a significant gap for a mutation tool.

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 succinct, with two sentences that lead with the core action ('Update a guide') and then immediately list the editable fields and the owner constraint. There is no wasted wording, though the listing of fields could arguably be trimmed since the schema already enumerates them.

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?

The tool has no output schema, and the description does not specify the return value, error handling, or whether the update is partial or full replacement. It also misses the cannibalisation side effect that is tucked into the schema. While the schema covers parameter semantics, the description lacks the operational context an agent needs to safely invoke this mutation tool.

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 already provides 100% description coverage for all seven parameters, including the cannibalisation side effect for the group parameter. The description merely lists the field names without adding any new semantic meaning beyond what the schema already offers, so the baseline of 3 applies.

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 clearly states the verb 'Update' and the resource 'a guide', then enumerates the specific editable fields (group, status, share state, linked URL, meta, hidden expressions). This distinguishes it from sibling tools like create_guides, delete_guide, and get_guide, leaving no ambiguity about its function.

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 implies that this tool is for modifying an existing guide's editable fields, but it does not explicitly contrast it with alternatives or state when not to use it. The only contextual guidance is the owner permission requirement, which is a precondition rather than a usage decision.

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