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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the description's job is to add operational context — and it does: items are priority-ordered, include_markdown roughly doubles response size, verbose expands each item with rationale and steps. It does not describe rate limits or failure modes, which keeps it below 5.

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?

Front-loads what the plan contains, then layers in flags and workflow in four dense sentences with no filler. It is slightly overloaded, packing paging, markdown format, fix applicability, and the verification loop into one paragraph, but every sentence carries information an agent needs.

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 9-parameter tool with no output schema, the description does substantial work: it sketches the returned item structure, gives a concrete Markdown heading format, and explains the fix-then-rescan loop. What's missing is how project_id/codes interact with defaults and what an empty plan means, but nothing critical to invoking it correctly is absent.

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; the description still earns credit by adding cost/behavior semantics the schema lacks — include_markdown 'doubles the size', max_pages truncation is recoverable via list_issues, and paging is framed as limit/offset. It does not clarify the limit-vs-max_items duplication or the codes format, leaving some ambiguity.

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 ('an ordered, implementable plan for every open problem') and enumerates the payload shape (what to change, where, on which URLs, target example). This clearly separates it from siblings like list_issues (raw issue listing), get_issue (single item), and get_plan_status (progress rather than content).

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?

Gives concrete downstream workflow: apply items via apply_fix, then call start_scan and get_site_health to confirm what cleared. It also routes overflow to list_issues code=… when max_pages truncates URLs. It stops short of an explicit 'use this instead of X when…' exclusion against get_issue or list_issues for the top-level case, so it isn't a full 5.

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