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

Annotations mark the operation as destructive, and the description adds valuable behavioral details: matching is literal, duplicate matches cause rejection rather than guessing, all=true is the escape hatch, and omitting replace deletes the matched text. It does not mention concurrency behavior around if_updated_at, but the schema already covers that parameter.

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 description is compact and front-loaded with the core action, then moves through literal matching, an illustrative example, duplicate handling, and routing advice. Every sentence earns its place and there is no redundant or filler 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?

Given the annotations, output schema, and sibling context, the description is complete enough for an agent to invoke the tool correctly. It covers the operation, safety caveats, disambiguation strategy, and when to choose the sibling update_note, with no significant gap left to inference.

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 80%, so the schema already documents most parameters. The description adds real semantic value with the literal-match warning, a concrete checkbox example, and an explanation of when all=true is needed due to duplicate-match rejection, going beyond the raw parameter defaults.

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 opens with a specific verb and resource: 'Change one span of a note without resending the rest of it.' It clearly differentiates this tool from update_note by saying it is preferred for any edit smaller than the whole note, so an agent can identify its exact role among the siblings.

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 description gives explicit routing guidance: 'Prefer this over update_note for any edit smaller than the whole note.' It also explains what to do when the target text is ambiguous ('add surrounding text or pass all=true'), giving the agent concrete decision criteria.

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