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

Annotations already declare a safe read-only profile. The description adds genuine beyond-schema context by clarifying that screenshots are returned as URIs under a documented endpoint rather than inline bytes, which materially helps the agent handle the response.

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 tightly written sentences, the retrieval purpose front-loaded and the response-handling caveat second. No filler.

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 must characterize the return, and it does: full evidence, Markdown summary, and screenshot URIs with a path to fetch them. Adequate for an agent to call and consume the result correctly.

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 coverage is 100% and there is only one parameter (runId) already documented in the schema. The description's reference to a past test run and the :runId path do not add meaning beyond the structured field, 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 (retrieve) and resource (full evidence and Markdown summary from a past test run), and the phrase 'past test run' distinguishes it from the write-oriented sibling run_test. It does not name a sibling explicitly, so it stops short of a 5.

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?

'from a past test run' implies this is the post-run retrieval step following run_test, so usage is implied rather than stated. There is no explicit when-to-use, when-not, or alternative tool named.

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