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

Annotations already declare readOnlyHint=false and destructiveHint=false, but the description adds critical behavioral context: the note is visible only to team members and never to the respondent, the 2000-character limit, the optional recordId context, and the non-idempotent timeout behavior. The non-idempotency warning is especially valuable because it directly affects how an agent should handle retries.

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?

Three sentences with zero waste. The core action and visibility constraint are front-loaded, the character limit and optional parameter are stated compactly, and the non-idempotency warning is placed at the end where it is most actionable. Every sentence earns its place.

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 3-parameter tool with 100% schema coverage, an output schema, and annotations covering the safety profile, the description is complete. It covers the action, scope, visibility, limits, optional parameter semantics, and retry behavior. Nothing an agent needs to call it correctly is missing.

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?

Schema description coverage is 100%, so the schema already documents all three parameters. The description adds meaning by explaining the purpose of the note ('internal follow-up'), the visibility constraint, and the optional recordId as 'context'. It doesn't add syntax details, but the schema already covers those, so a 4 is appropriate.

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 a specific verb ('Write'), a specific resource ('internal follow-up note on a lead'), and a clear scope ('of the current team'). It also distinguishes itself from reading notes by pointing to get_lead(includeComments: true), and the sibling list shows no other add-comment tool, so there is no 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?

The description explicitly says when to use this tool (to write an internal follow-up note), what it is not for (visible to team members only, never to the respondent), and how to read existing notes (get_lead with includeComments: true). It also gives a clear retry policy: check first, then retry only if the note is really missing. This is explicit when/when-not guidance.

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