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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by itemizing exactly which data groupings come back, which matters because no output schema exists; it stops short of describing text formatting, ordering, or volume of the returned numbers.

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?

A single sentence that front-loads the framing ('the performance page's numbers as text') and then lists the payload components with no filler. The only soft spot is the opaque 'as text' phrasing, which could have been a few words more specific at negligible cost.

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 no-parameter, read-only, no-output-schema aggregate read, the description covers what an agent needs to decide to call it and roughly what will come back. Residual gaps are minor: the PST acronym and the exact shape of the 'as text' payload are not spelled out.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the empty schema with additionalProperties=false is self-explanatory. Baseline 4 applies.

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 resource (the performance page's numbers) and enumerates the three concrete contents returned: latest PST scored against minimums, PST history, and plan completion counts. That makes it distinguishable from single-result siblings like get_pst_result or list_pst_results, though the acronym 'PST' is never expanded.

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 by the enumerated contents — an agent can infer this is the aggregate overview versus a single PST result. There is no explicit when-to-use statement, no when-not guidance, and no sibling is named as an alternative, despite several closely related tools (get_pst_result, get_today, get_week) being present.

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