get_texel_density

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

With no annotations present, the description carries the full burden and does reasonably well: 'Measure' plus the Returns block make clear this is a non-mutating query, and it specifies that surface area is reported in world scale. Gaps remain around failure behavior (no UV map, object not in scene) and whether it operates on the named object or the active one.

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 definition is front-loaded with the concept before the Args/Returns blocks, and every line is functional. The game-art benchmark sentence is slightly tangential but earns its place by giving the agent a sanity-check reference for the returned number.

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?

For a two-parameter read-only measurement tool with an output schema present, this is nearly complete: parameters are documented, the unit convention (px/m, m^2 world scale) is stated, and the returned fields are named. Only the sibling relationship with set_texel_density and edge-case behavior are missing.

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 0%, so the description must compensate, and it does: object_name is qualified as a 'mesh object with a UV map' (a real prerequisite the schema lacks), and texture_size is explained as the pixel width the UVs are authored for. It omits that texture_size defaults to 1024, which matters for interpreting the returned density.

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 — 'Measure texel density' — and even defines the metric ('how many texture pixels cover one metre of surface'), so the agent knows exactly what is computed. It does not, however, acknowledge the obvious sibling set_texel_density, which is the write-side counterpart an agent could easily confuse it with.

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?

Usage is only implied: the mention of matching density across assets and game-art targets of 512/1024 px/m suggests this is a diagnostic/QA check. There is no explicit statement of when to call this instead of set_texel_density, and no note about preconditions failing (e.g. object lacking a UV map).

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