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

Annotations already declare read-only, idempotent, and open-world behavior, so the description's 'Read-only' line is redundant. However, it adds useful operation-specific behavior: unknown ids return not found, no API key is required, and the id is a canonical slug rather than a free-form name. This goes beyond what the annotations alone provide.

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 core action is front-loaded, followed by use cases, prerequisite, and parameter format. It is compact and each sentence earns its place; the only slight redundancy is 'Read-only' duplicating the annotation.

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?

With an output schema available, the description does not need to explain return values, and it covers the key prerequisites: resolve personId first, use exact id, not-found behavior, auth, and example triggers. The only omitted element (required rationale) is fully specified in the input schema, so the full tool definition is complete.

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 leaves personId as a bare string, so the description compensates with canonical examples ('vitalik-buterin', 'satoshi-nakamoto') and clarifies the exact-id requirement. The rationale parameter is well documented in the schema, but the description's Params section mentions only personId, which is a minor gap.

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 opens with a specific verb and resource: 'Get the profile of one person in crypto by id', then lists the returned fields (name, bio, teams_count, positions, linked projects, social/code accounts). It distinguishes itself from sibling tools like getCoinById by being person-focused and requiring an exact id.

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?

It gives concrete example queries ('who is Vitalik Buterin', 'background on Charlie Lee') and explicitly instructs the agent to resolve personId via search or resolveId with type 'people' first. It also states the negative case: do not pass a name, the tool needs the exact id. This fully routes the agent to the right tool and prerequisite.

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