Read a saved crawl's data

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds real behavior beyond that: the data is a cached snapshot of the most recent completed run only, and calling it never triggers a crawl — an important expectation-setting detail.

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 sentences, both load-bearing, with the read-only, no-run-started constraint front-loaded before the usage hint. Nothing is repeated from the title 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 no output schema, the description usefully states which run's data is returned and that it is never mutated, which compensates for the missing return-value documentation. Pagination and response-shape behavior are left entirely to the schema, which documents the output param but no return format.

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 the nested output object, limit, and preview_chars are all documented in the schema with defaults and semantics. The description adds no parameter-level guidance, 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 verb and resource ('Read the data a saved crawl already collected') and pins the exact data set ('most recent completed run'). The phrase 'Never starts a crawl' cleanly separates it from writ_run_saved_crawl and writ_crawl_site without needing to open either 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?

'use this when you want what is already there, at any age' gives a clear condition for selection, and the negative clause rules out triggering a fresh run. It stops short of naming the alternative tool (writ_run_saved_crawl) for the fresh-run case, leaving that inference to the agent.

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