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

The description goes well beyond the annotations by disclosing billing behavior (1 remediation credit per document, $2.99, charged to members and non-members, explicitly excluded from membership), a 24-hour expiry on the returned download URL, and the exact contents of the returned zip. Those are non-obvious side effects and constraints an agent could not derive from readOnlyHint/openWorldHint/destructiveHint.

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 first sentence front-loads the capability and its three steps; cost and return-value details follow in a logical order with no filler. The parenthetical price explanation is slightly dense but carries real decision-relevant information, so there is little waste.

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 paid, non-idempotent mutation with an output schema, the description covers cost, preconditions, and deliverable contents well. The one notable omission is whether re-running on the same document incurs another credit (relevant given idempotentHint=false, i.e., repeat runs are not deduplicated).

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 the schema already documents both 'url' (public URL, max 50MB) and 'title'. The description repeats the public-URL constraint but adds no new meaning about how 'title' affects metadata or file naming beyond what the schema states. Baseline 3 applies.

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 uses a specific verb and resource ('Auto-fix a PDF for accessibility') and enumerates the concrete operations performed: metadata injection, auto-tagging, veraPDF re-audit. The 're-audits' wording distinguishes this remediation pipeline from the sibling eap_check_pdf, though it never names that sibling explicitly.

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 requirement to 'Pass a publicly accessible URL of the PDF' gives the precondition for invocation, and the cost note serves as a soft gating signal. However, there is no explicit when-to-use guidance relative to eap_check_pdf (audit vs. remediate) or eap_export_pdf, leaving the agent to infer the workflow ordering.

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