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

Annotations only cover safety/idempotency, yet the description goes well beyond them: it discloses the claim-quote validation gate on body edits, that the error names the offending quotes, that line breaks/case/curly quotes are normalized (matching save_claim), and that non-note sources are rejected. These are exactly the runtime surprises an agent needs to anticipate.

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 and the update contract are front-loaded, and every sentence carries information (refusal rule, error behavior, normalization, sibling cross-references). The refusal paragraph is dense, but nothing is redundant or 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 annotations, a full input schema and an output schema already present, the remaining burden is failure modes and cross-tool routing — both covered in detail (quote-conflict refusals, source-type refusals, save_claim remediation). An agent has everything needed to call it correctly or know when not to.

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 baseline is 3, but the description adds the partial-update contract ('only the fields that change') and the semantic constraint that body replaces the old text wholesale and is validated against citing claims. That is real meaning beyond the schema, though id/url/title get no further clarification.

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 names a specific verb (edits) and resource (a pasted note / source with type note), enumerates the editable fields (title, body, link), and explicitly scopes out the neighboring source types ('a drive_doc syncs from Google Drive and is edited there'). An agent can distinguish it from add_source, delete_source and save_claim 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?

It gives an explicit invocation rule ('Pass id and only the fields that change'), states concrete when-not conditions (body edits are refused when a citing claim's quoted text would no longer be present; other source types are refused), and routes the agent to the alternative tool ('revise those claims with save_claim first, or keep the text'). Nothing about when to pick this tool is left to inference.

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