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

With annotations already indicating readOnlyHint=false and destructiveHint=false, the description adds key behavioral context: it is a non-destructive patch that 'does not replace other objects', it requires a valid revision ('Stale revisions fail; read again before retrying'), and it returns the new revision. It also warns about the editToken ('Never place it in a URL or public answer'). These are valuable behavioral disclosures beyond what annotations provide.

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: the first sentence captures the essential behavior, the second states prerequisites, and the third gives a practical instruction. No filler; every sentence earns its place.

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 tool's complexity (5 params, nested objects, revision management), the description covers the critical context: read before editing, stale revisions fail, editToken security, and the subobject replacement subtlety. A minor gap is that it doesn't explicitly spell out what the output looks like, but there's no output schema and the context is largely sufficient for an agent to invoke correctly.

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 coverage is 100%, so the schema already documents all parameters. The description adds meaning beyond the schema: it clarifies the semantic distinction between patch vs replace ('without replacing other objects'), warns that style/start/end replace the whole subobject and to read first, and emphasizes the editToken security constraint. This exceeds the baseline 3 for full schema coverage.

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 states a specific verb ('Patch') and resource ('one existing object without replacing other objects'), and the title adds that it edits a figure or connector. It clearly differentiates from sibling tools like add_shape and remove_shape by emphasizing patching an existing object rather than adding or removing.

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 explicitly says when to use this tool ('Patch one existing object...') and gives a clear directive: 'Read the drawing first to inspect existing fields.' It also implicitly distinguishes from set_drawing (which likely replaces the whole drawing) and add_shape. The requirement for editToken and latest revision provides usage context.

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