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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description stays consistent, adding genuinely non-obvious context: reports expire after 90 days and the identifier can be either a raw id or a full link. It does not say what happens when a report has expired or is not found, which is the remaining behavioral gap.

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 dense sentence that front-loads the purpose and then the return contents, followed by a short retention note. Slightly run-on with the parenthetical URL breaking the flow, but no filler sentences.

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?

No output schema exists, and the description compensates by enumerating the returned fields (status, per-pixel grades, problems with explanations and fix guide links, checklist). Combined with accepted input forms and the 90-day lifetime, an agent has enough to call it and interpret the result.

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 the baseline is 3, but the description adds information the schema lacks by giving the concrete link form 'https://ispixelworking.com/r/<id>', which clarifies what 'report link' means beyond the schema's 'Report id ... or report link'.

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?

States a specific verb and resource ('Read the result of a check') and enumerates exactly what comes back: status, per-pixel grades, problems with fix guides, checklist. It partially distinguishes itself from list_findings and get_fix_guide by describing those artifacts as part of one report, but never names the siblings, so an agent must infer the boundary.

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: you read a report by id or link. No explicit when-to-use/when-not, and no mention of the alternatives (check_page to run a new check, list_findings for a narrower view, get_fix_guide for a single guide). The 90-day retention is a useful constraint but not routing guidance.

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