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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds two genuinely non-obvious behaviors — that timestamps are UTC and that the `to` boundary is exclusive — but says nothing about result ordering, default sort, or how `query` matches, which are the remaining operational unknowns.

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, zero filler, with the core purpose front-loaded and the subtle caveat trailing it. Nothing can 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 7-parameter, no-required-argument listing tool with no output schema, the description is minimally adequate: it covers filtering and pagination but leaves the search semantics of `query` and the shape/ordering of results unexplained. An agent could call it, but not confidently predict what it gets back.

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?

With 0% schema description coverage the description must carry parameter meaning, and it partly does: it names pagination, status, source and UTC date filters, and clarifies boundary inclusivity. However, `query` (the free-text search parameter) is never mentioned or explained, and `page`/`size` get no semantics beyond the word 'pagination'.

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 ('Search screenshot history') plus the filter dimensions it supports, which clearly separates it from single-item siblings like get_screenshot. It doesn't name a sibling explicitly, so it stops short of a 5.

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 statement of when to use this versus get_screenshot, get_screenshot_result, or list_bulk_captures — the agent must infer the routing. Filter categories are mentioned but are not framed as usage conditions or exclusions.

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