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

Annotations already declare destructiveHint=true and readOnlyHint=false, but the description adds real behavioral content beyond them: this is a full replace, not a merge, and passing an empty list is a deletion. That is exactly the kind of destructive-scope detail annotations cannot convey. It still omits the role of expected_revision as a concurrency guard, which matters for a destructive write.

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?

Two sentences, the mutation semantics front-loaded, then the boundary against the sibling. No filler and no repetition of schema or annotation content.

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?

There is no output schema and no return-value discussion needed, and the annotations cover the safety profile. But for a destructive, revision-guarded write with four fully undocumented parameters, the description omits the concurrency requirement (expected_revision) and dry-run behavior, which an agent needs before calling it.

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 must carry parameter meaning, and it only partly does: 'chapters' is characterized as an ordered list whose emptiness deletes. The required expected_revision token, the dry_run flag, catalogue_id, and the 300-item cap are entirely unexplained, leaving an agent to guess at the concurrency contract.

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+resource ('replaces the table of contents') and adds the exact semantics of an edge case ('an empty list removes it'). It also distinguishes itself from the sibling that handles all other reader settings, so an agent can tell the two apart without opening either 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?

Explicitly scopes the tool to the table of contents and names the alternative (foliade_update_catalogue) for every other setting, which is a genuine when/when-not rule. It does not mention foliade_import_chapters, which appears to be a competing bulk-loading path, nor when to prefer dry_run.

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