platform_limits

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

With no annotations provided, the description carries the burden of behavioral disclosure. It clearly states that the tool lists platforms with their limits, units, explanatory rationale, and sources, and frames it as a read-only informational operation. It does not explicitly mention side effects or authentication, but for a simple listing tool, this is adequate.

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?

The description is two sentences of appropriate length. The first sentence front-loads the action and output contents, while the second sentence adds practical usage guidance. Every clause contributes value, and there is no redundancy or filler.

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?

The tool is simple: one optional parameter, no output schema, and modest complexity. The description enumerates the output fields (platform, limit, unit, reason, source) and provides a use case. It could be slightly more explicit about the response format, but it is sufficiently complete for an agent to select and invoke the tool correctly.

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?

The input schema provides 100% coverage: the only parameter, 'platform', is fully described with an enum of allowed values and a clear description ('Limit the response to one platform. Omit for all of them.'). The description adds no additional parameter-level detail, but none is needed given the schema's completeness.

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 opens with the specific verb 'List' and clearly identifies the resource: platforms known to the server, along with their limits, units, rationale for non-character-count units, and data sources. This distinguishes it from sibling tools like check_post and check_post_all, which focus on post-length validation rather than enumerating platform limits.

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?

The description explicitly states when to use the tool: 'Use it to explain a result or to see what is covered.' This provides clear context. However, it does not explicitly mention when not to use it or alternative tools, so it stops short of a full 5.

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