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

Annotations already declare openWorldHint=true and non-idempotency, but the description adds output-size guidance (~750-1.5k tokens), a real behavioral trait not present in structured fields. It does not disclose that the call is paid (the max_sats parameter implies a charge), which is the one notable behavioral omission.

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 plus a fragment, with the capability and its included artifacts front-loaded and the routing advice immediately after. Every clause 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?

An output schema exists so return structure need not be explained, and the description covers scope, sizing, and usage adequately. The only shortfall is that the cost dimension implied by max_sats is never addressed.

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 repo format, ref defaulting, path skipping rules, and max_sats are all documented in the schema. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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 resource (GitHub repo) and enumerates exactly what the digest contains — tree, README, entry points, commits — plus its size. An agent can immediately distinguish it from siblings like read_webpage, read_pdf, or page_metadata without opening a schema.

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?

Gives explicit when-to-use ("Use on medium/large repos") and when-not ("Skip if you only need the README: read it directly"), naming the cheaper alternative and the condition that selects it. Nothing is left to inference.

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