get_unsubscribe_info

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

No annotations are supplied, so the description carries the full burden, and it discharges the most important part by stating 'Does not change anything' — an explicit non-mutation guarantee. It also enumerates the categories of result (one-click, mailto, link), which effectively describes the return shape in the absence of an output schema. It stops short of describing edge-case behavior, such as a message with no List-Unsubscribe header or an unsupported/unverified one-click URI.

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 short sentences with no filler, and the read-only guarantee is placed last as a clean safety note after the substantive purpose. Nothing here could be cut without losing information.

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 one-parameter read tool with no annotations and no output schema, the description covers purpose, safety, and the kinds of results returned. The remaining gaps are the missing-header case and the semantics of the 'id' argument, both of which the agent may need in order to interpret an empty or partial result.

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% for the single required 'id' parameter, so the schema contributes no meaning. The description only indirectly identifies it as the message whose headers are read ('a message's List-Unsubscribe headers'), which is enough to infer the parameter's role but adds no format, source, or constraint details.

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 gives a specific verb and resource: read a message's List-Unsubscribe headers and report how to leave the mailing list. It also names the three response modes (one-click, mailto, link), so the agent knows exactly what comes back. It does not explicitly distinguish itself from the sibling 'unsubscribe' tool, which is the one it is most likely to be confused with.

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 only implied: an agent can infer this is the inspection step before acting. There is no explicit statement such as 'use this to inspect, then call unsubscribe to actually act', and no guidance on what to do when no List-Unsubscribe header is present. The read-only framing hints at when-not-to-use, but only indirectly.

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