get_evidence_image

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description still adds real context: the return is an inline PNG (not a path/URL), and the tool will not fetch arbitrary URLs or paths — a useful security boundary. It stops short of mentioning size limits or error behavior for an unknown digest.

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 with zero filler; the core action and its inputs come first, and the negative constraint follows as a useful qualifier. Every clause earns its place.

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 correctly specifies the return payload (inline PNG), which is the key missing structured information. Combined with the digest provenance and the security constraint, an agent has what it needs, though failure modes for a stale or unknown digest are unaddressed.

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 0%, so the description must carry the load, and it does partially: it explains that the digest is a content hash obtained from get_flow_evidence, which the raw regex pattern alone would not convey. The project parameter's meaning is only implied by its name, so one gap remains.

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 ('Return a stored PNG inline') plus exact scoping ('for a project and content hash'), and names the sibling get_flow_evidence that produces the hash. An agent can distinguish this from get_flow_evidence or get_change_evidence without opening any 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?

Gives clear routing guidance by naming get_flow_evidence as the source of the digest, and adds a when-not boundary ('Never fetches arbitrary URLs or paths'). It does not explicitly contrast against every sibling, but for an image-retrieval tool the alternative space is effectively empty, so this is close to sufficient.

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