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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds meaningful context by specifying that similarity is based on public repository, language, location, and profile signals, and importantly clarifies that this is not a suitability judgment. This goes beyond what annotations 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 description is compact, front-loaded with the use case, and every sentence adds value. The example is short and directly demonstrates a realistic call. There is no filler or repetition.

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 simple two-parameter, read-only, idempotent tool with a full input schema and an output schema, the description provides all necessary context: when to use it, what similarity means, and a caveat about suitability. Nothing essential 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 fully documents both login and limit. The inline example reinforces usage but does not add significant meaning beyond the schema definitions. Baseline 3 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 and resource: it finds alternatives similar to a known GitHub login. It clearly differentiates from sibling tools like search_developers or match_developers_to_repository by focusing on similarity to an existing profile, not general search or repository matching.

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 "Use when the user wants alternatives similar to a known GitHub login," providing clear context for when to invoke the tool. It does not explicitly list exclusions or alternative tool names, so it stops short of a full when-not/alternatives guide.

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