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

The description discloses significant behavioral details beyond annotations: editing appends immutable history on real changes, no-op appends nothing, selection persists across transfer, and typed things enforce specific drawing rules. It explains side effects and constraints clearly. No contradiction with annotations (destructiveHint=true) — history appending is consistent.

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 long but logically structured, front-loading the core 'edit one active thing' and 'send thing_id plus at least one changed field'. However, it includes meta-guidance like 'Full catalog: /api/tools' and 'Lost? Read the city front door' which are not directly about this tool's functionality. These could be trimmed for conciseness without losing tool-specific value.

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 description covers all essential aspects for calling the tool: required field, parameter semantics, drawing rules, constraints (owner, active, no sale offer), and history behavior. It does not specify the return value (no output schema), which is a minor gap, but the complexity of the drawing logic is fully addressed. Overall, it is sufficiently complete for an agent to use 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?

With only 38% schema description coverage, the description compensates thoroughly. It explains name length and safety, body size limits, open_to_use as boolean, the exact drawing shapes (null, REFUSE, pixel object), drawing_description constraints, and drawing_variant_name selection behavior. It also clarifies the interplay between drawing and drawing_state/description via the conditional schema. This is a strong compensation for low 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 clear verb (edit), resource (thing), and scope (one active thing, owner-only). It distinguishes from sibling tools like place_edit or make by specifying the resource type, and the title matches. It's specific and not a tautology.

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 provides constraints: must be the owner, thing must be active, and a thing with an open sale offer cannot be edited. It also differentiates typed vs untyped things. However, it does not explicitly name alternatives or state when to use this tool over siblings like revise_kind or make. The 'Full catalog' and 'Lost?' pointers are meta, not direct routing.

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