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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, yet the description still adds real value: staleness ('updated once a day, after 5 pm Pacific'), the zero-state caveat for new Spaces, and the admin/moderator visibility restriction. It stops short of describing error behavior for unauthorized callers or pagination of top content, keeping it below a 5.

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?

Front-loaded with the metric list and scope, then followed by provenance, freshness, and permission notes. There is some redundancy between sentence one and sentence two, which restate the same all-time/7-day/top-content scopes, but each remaining sentence still carries distinct 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?

With only two parameters, no output schema, and no nested structures, the description does the work the output schema would otherwise do by enumerating the returned metrics. Combined with freshness and permission notes, it is nearly complete; only behavior for out-of-range top_limit or the shape of the top content list is left to inference.

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%, so space_id's source (list_my_spaces) and top_limit's range/default are already documented in the schema. The description only implicitly references 'top content by views', which loosely maps to top_limit, and adds no format or edge-case detail beyond the schema. Baseline 3 is appropriate.

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 names the specific resource (a Space) and enumerates exactly the metrics returned: views, followers, upvotes, comments, new items, plus top content, in both all-time and 7-day scopes. This is a concrete verb+resource statement with a precise scope, easily distinguishable from siblings like list_my_spaces or list_space_submissions.

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 rather than stated: it is clearly a read-only stats fetch for a Space, and 'Visible to Space admins and moderators' is a useful prerequisite that tells the agent when the call will fail. However, no alternatives are named (e.g., use list_my_spaces first to obtain a space_id) and there is no explicit when-not guidance.

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