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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds value by disclosing that the base64 body is decoded and listing the return fields (entry kind, digest, signature, certificate, timestamp, inclusion proof). No contradiction with annotations.

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?

Three compact sentences, each earning its place: core capability with output fields, usage branching, and a concrete example. The description is front-loaded with the verb and resource, with 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?

For a single-parameter read-only tool with no output schema, the description compensates by enumerating the returned fields. Minor gaps are the absence of out-of-range error behavior and the terse 'Keyless' note, but nothing an agent needs to make the call is missing.

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 schema already explains the parameter semantics (position 0..tree_size-1, referenced by rekor_log_info). The description's example (log_index 500000) duplicates the schema example, so it adds little beyond the schema baseline.

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') and identifies the retrieval key (integer position in the log). It enumerates the decoded fields returned and implicitly distinguishes itself from the uuid-based sibling rekor_entry.

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?

Explicit guidance is given: 'Use this to walk the log; use rekor_entry when you have a uuid.' This names the alternative and the exact condition that selects it, so an agent does not need to infer when this tool is appropriate.

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