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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered. The description adds the mild behavioral note that `include` expands the response with the parent project chain, but says nothing about error behavior or auth needs; with annotations bearing the load, a 3 is appropriate.

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 short sentences, zero waste, with the core fetch action front-loaded before the optional parameter note. 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 simple single-resource read with full annotation coverage, a complete schema, and no output schema requirement, the description supplies what an agent needs to invoke it correctly. Only minor gaps remain, such as not explaining the shape of the expanded response.

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% and both parameters are documented in the schema itself, including the whitelisted `include` values. The description restates the `include` effect ('load the parent project chain') at a high level, adding only marginal meaning over the schema. Baseline 3 applies when the schema does the heavy lifting.

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 ('Fetch a single segment by its numeric id'), clearly separating it from list-segments-tool and the mutation tools. It does not explicitly name a sibling to route the agent, but the singular scope plus id requirement makes the intent unambiguous.

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 mentions that `include` may be optionally passed to load the parent project chain, which implies one usage pattern, but there is no guidance on when to prefer this tool over list-segments-tool or when `include` is worth the extra payload. Usage is implied rather than stated.

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