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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds value by explaining that the tool is keyless and that entries are tamper-evident, and it details the output structure. It does not contradict any annotation. The lack of error-handling notes is minor given the read-only, idempotent nature.

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?

The description is a single, information-dense sentence followed by a concrete example. It front-loads the verb and resource, then packs in the essential output details and a usage hint. There is no wasted verbiage; every clause contributes to agent decision-making.

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?

The tool has one required parameter, annotations cover safety, and there is no output schema. The description compensates for the missing output schema by enumerating the exact fields returned, and it provides a realistic example. Nothing essential is missing for an agent to call this tool 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% (the uuid property is described), so the baseline is 3. The description adds meaningful context: it specifies that the uuid is the 80-hex id returned by rekor_search_by_hash and provides a concrete example. This clarifies the provenance and format of the parameter beyond the schema's generic '64 or 80 hex characters'.

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 opens with a specific verb and resource: 'Fetch one Sigstore Rekor transparency-log entry by its uuid.' It then enumerates the decoded fields (entry kind, digest, signature, certificate, integration time, Merkle proof), which fully clarifies the tool's function. It also distinguishes itself from siblings by referencing the uuid produced by rekor_search_by_hash and implies a contrast with rekor_entry_by_index.

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?

The description explicitly ties the uuid parameter to the output of a sibling tool ('the 80-hex id rekor_search_by_hash returns'), giving a clear precondition. It does not explicitly exclude rekor_entry_by_index or state when to prefer it, but the context strongly implies that this tool is for uuid-based lookups, which is sufficient guidance for an agent.

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