Get README at commit

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

Annotations already declare readOnlyHint, openWorldHint and idempotentHint, so safety is covered. The description adds genuinely new behavioral context beyond that: this is a historical/snapshot read ('Wayback view') and it costs 10 credits, a real budget constraint. It does not describe response size or truncation behavior.

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: the core semantics and provenance first, then the cost note. No filler, no restatement of the title, and the distinguishing qualifier ('Wayback view') is front-loaded.

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 2-param read tool with no output schema, the description conveys what is returned (the exact README content at a commit) and how to obtain the commit. It leaves the return encoding (raw markdown vs JSON wrapper) unspecified, a minor gap given no output schema exists.

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 (id, commit) are documented in the schema with format hints and examples. The description only restates that commit comes from list_readme_drifts, adding no syntax or format detail beyond the schema, so 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 verb and resource ('the exact README of one model at one commit sha') and frames it as a 'Wayback view', which separates it cleanly from get_model and from the sibling list_readme_drifts that only lists drifts. The endpoint path is included, further pinning the resource.

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?

Explicitly tells the agent where the required commit sha comes from: 'Use a commit_sha from list_readme_drifts', which routes between siblings. It stops short of stating when not to use this tool (e.g. for the current README, use get_model), so it is strong but not full guidance.

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