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

readOnlyHint=true already declares the safety profile, so the description's remaining job is to add context. It does add real value by flagging that the payload contains personal data and that webhook URLs are redacted, which prevents wasted attempts to read them. However, it says nothing about not-found behavior, permissions, or rate limits, so the disclosure stops at one clause.

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, front-loading the entity and its scope before the endpoint mapping; nothing is padded. The trailing "Sorry: GET /v1/pages/{page_id}/subscribers/{subscriber_id}" is largely restating the name and parameters, so it is close to but not quite free of waste.

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 burden of explaining what comes back, and it only notes the sensitive/redacted aspects rather than the shape of the subscriber record. For a simple two-required-parameter read this is adequate but leaves the agent guessing about the response fields.

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% and the schema itself documents both page_id (with a pointer to sorryapp_list_pages) and subscriber_id. The description adds no format, aliasing, or type detail beyond that, so the baseline 3 for a fully described schema is the right ceiling.

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 ("Get one subscriber of a status page") and pins it to a single REST endpoint, which cleanly separates it from sorryapp_list_subscribers. It stops short of naming the sibling it displaces, but the singular "one subscriber" is enough for an agent to distinguish them.

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?

There is no explicit when-to-use or when-not-to-use guidance, no mention of alternatives such as sorryapp_list_subscribers, and no note about what happens when the ids are unknown or the subscriber is absent. The agent must infer the retrieval use case purely from the name and endpoint.

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