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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely new behavior: legacy addresses are resolved automatically and missing/hidden identities yield null, which tells the agent how to interpret failures.

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?

Two compact sentences, front-loaded with the operation and scope, followed by edge-case behavior. No filler or repetition of the name or schema.

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 one fully documented parameter and annotations covering the safety profile, the definition is nearly sufficient. Since there is no output schema, the mention of 'inclusion evidence' and the null-return case carries the return semantics, though the actual evidence payload is only hinted at.

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 baseline is 3; the schema already defines identity as owner/repo or a GitHub URL. The description goes further by noting that identities can be stale addresses that get resolved and can be hidden, adding acceptance semantics beyond the schema's format hint.

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?

States a specific verb (read) and resource (one public GitHub project) plus the returned evidence, which is clearer than a bare name restatement. The word 'one' implicitly contrasts with the sibling search_projects, but the sibling is never named, so the differentiation is left to inference.

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 phrase 'Read one public ... project' implies a single-identity lookup versus the plural search_projects, but there is no explicit when-to-use or when-not-to-use guidance and no named alternative. Usage is inferable rather than stated.

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