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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description still adds value beyond them by disclosing the return shape ('fix_pack text plus fill_in') and the required post-processing step of asking the user and substituting [[NAME]]. It does not cover size, pagination, or what happens for a run with no failures.

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?

Three short sentences, front-loaded with the deliverable, followed by the return contract and the post-processing instruction. Fragmentary style is efficient, though 'builder: emergent, lovable, nextjs or generic' reads as schema notation rather than prose.

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 correctly covers the return shape and the fill_in placeholder workflow, plus the paid-plan prerequisite. An agent could call this and hand over the result correctly; only the no-failure case and the meaning of run_id remain unstated.

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 0%, so the description carries the burden and largely does: it enumerates the accepted builder values (emergent, lovable, nextjs, generic) that the schema leaves as an unconstrained string with a default. run_id's meaning is only implied by 'a run's failures', so it is not fully spelled out.

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 deliverable (a builder-specific, copy-paste fix pack) scoped to 'a run's failures', which is clearly distinct from the sibling get_findings, get_report, and recheck tools. It stops short of naming those siblings, so differentiation is inferred from the resource rather than made explicit.

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?

Implies the trigger condition (a run that has failures) and adds a real gating constraint ('Paid plans'), but never says when to prefer this over get_findings or get_report, or what to do if the plan is unpaid. Usage context is present but not comparative.

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