Get attachment file from esa

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

Goes well beyond the readOnly/non-destructive annotations by disclosing the actual return-shape logic: base64 for JPEG/PNG/GIF/WebP under 30MB, signed URLs otherwise or when forceSignedUrl is set. This tells the agent what payload to expect and why, which is exactly the behavioral context annotations cannot carry.

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 tight sentences, front-loaded with the core action before the conditional return-format rules. Every sentence carries information; the opening 'with signed URLs' phrasing is slightly awkward but quickly clarified.

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 carries the return-value burden and does so fully by specifying the two response modes and the conditions that select them. An agent has everything needed to call this correctly and interpret results.

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%, so all three parameters are already documented, and the description only restates the forceSignedUrl effect. Baseline 3 is appropriate since the schema does the heavy lifting on parameter meaning.

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 ('Retrieves an attachment file from esa') that is unambiguous and distinct from every sibling, none of which deal with attachment files. An agent can identify this tool's domain without opening the 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?

Usage is implied by the purpose (fetch an attachment when you have its URL), and the description explains the base64/URL branching, but it never states when to prefer this tool over alternatives or any prerequisite. No explicit when-not or alternative routing is provided.

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