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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description's contribution is disclosing that the response is enriched with deals and timeline items, which signals a heavier payload than a bare record. It does not say what happens for an unknown ID or whether the timeline is bounded/paginated.

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?

A single short sentence with the resource front-loaded and the payload detail in parentheses; there is no filler or redundant restatement of the title.

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 one-parameter read tool whose annotations cover safety and which has no output schema, the description does adequate work by naming the returned sections. It is incomplete on how to obtain a contactId and on the shape or size of the timeline, both of which an agent needs to call it correctly.

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 single parameter contactId has 0% schema description coverage, so the schema supplies only a name and type. The description does nothing to compensate: it never says where the ID comes from (e.g., list_contacts or search) or what format it takes. With one undocumented parameter, the description should be carrying this burden and is not.

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 and resource ("Get a CRM contact") and adds scope by naming the expanded payload: deals plus a timeline of activities, mails, and notes. That is enough to distinguish it from generic fetches, though it never names the nearest sibling (list_contacts) or clarifies the single-record nature explicitly.

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 when-to-use guidance, no statement of when to prefer list_contacts or search instead, and no note that a contactId is required. The only implicit cue is that it returns one enriched contact, which an agent must infer from the singular phrasing.

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