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

Annotations already provide readOnlyHint=true and destructiveHint=false, and the description adds behavioral detail by stating it validates specific contract aspects (nodes, edges, owners, accessibility, receipt-binding metadata) and explicitly says it does not mutate a canvas. This complements the annotations without contradicting them, though it doesn't describe return/validation errors or other side effects beyond what annotations cover.

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 two sentences, front-loaded with the core action and purpose, then added constraints. Every word earns its place, with no repetition of schema fields or annotation data. It is compact and easy to parse.

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?

The tool has a single parameter, a full output schema, and rich annotations, so the description does not need to explain return values. It covers the purpose, preconditions (before rendering), and non-behavior (does not draw), which is sufficient for an agent to select and invoke it correctly. Minor gap: it doesn't state what happens on invalid input (e.g., throw vs. return errors), but given the output schema presence, this is a small omission.

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?

The input schema has 100% description coverage with detailed property descriptions for the 'contract' object, so the schema already explains the parameter. The description adds no new parameter-level details beyond listing some fields already present in the schema, so it meets but does not exceed the baseline for high 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 clearly states the tool 'Validates a canonical StrategiX visual-spec contract before rendering', specifying the exact verb (validate), resource (contract), and scope (nodes, edges, owners, viewport policy, etc.). It also distinguishes itself from sibling tools by explicitly saying it does not draw or mutate a canvas, making it distinct from strategix_diagram_render.

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 phrase 'before rendering' implies the tool is a pre-rendering step, and the explicit note that it does not draw or mutate a canvas indicates when not to use it (when rendering is needed). However, it does not name alternatives like strategix_diagram_render directly or provide when-not-to-use conditions beyond not drawing, so it falls short of full explicit guidance.

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