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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), yet the description adds substantial context beyond them: the not_found semantics and their non-implication, that it inspects publicly reachable pages in a real browser with axe-core plus Evolize rules, and that it does not read source code so findings reference the rendered DOM. This is exactly the extra context the lower bar with annotations rewards.

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 purpose is front-loaded in the first sentence and each sentence carries useful information about behavior, return semantics, and scan mechanics. It runs long for a read-only getter, and the 'coding agent maps them to source' sentence is more advisory than necessary, but nothing is redundant 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?

With no output schema, the description usefully discloses the not_found return and that findings reference the rendered DOM rather than source lines. It stops short of describing the response shape or the meaning of limit/cursor paging behavior, but it is otherwise sufficient for an agent to call this 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?

Schema description coverage is 100%, so url, limit, and cursor are already documented with examples and ranges in the schema itself. The description adds no parameter-level detail beyond that, making the baseline 3 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?

States a specific verb and resource ('Retrieve an EXISTING public Evolize accessibility assessment for a website') and immediately distinguishes itself from sibling scan_website with 'this starts no scan and creates no work.' An agent can route between this and the scan tools without opening any schema.

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 'EXISTING' emphasis and 'starts no scan' clause effectively tell the agent to use this when a report may already exist rather than to trigger a new scan, and it warns that not_found carries no implication about site quality. However, it never names the alternatives (scan_website, get_scan_result) explicitly, so the routing is implied rather than stated.

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