lookup_transform

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the agent knows this is a safe, side-effect-free query. The description adds genuinely useful conventions beyond that — metres and quaternion order (x, y, z, w) — but says nothing about failure behavior (unknown/expired frame), whether the transform is the latest available or time-parameterized, or the tolerance for disconnected frames.

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?

One sentence, front-loaded with the core semantics, followed by the units and quaternion convention as a compact trailing clause. Nothing repeated from the schema and nothing extraneous.

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?

With two required parameters, annotation coverage, and an output schema that handles return-value documentation, the description is complete enough to call correctly. The only real gap is error/lookup-miss behavior, which matters for a ROS tf2 call but is not covered by the output schema.

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 0%, so the description must carry the burden, and it does: it defines the role of each parameter and supplies concrete example values, resolving the classic source-vs-target inversion. It stops short of stating whether frame names need a leading slash or how to reference a fixed world frame.

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 precise verb (express/look up) and resource (pose of source_frame in target_frame) with the tf2 semantics named explicitly, which pins down the direction of the transform — the exact thing that is ambiguous in frame math. No sibling tool performs a transform lookup, so an agent can route here unambiguously.

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 implied rather than stated: an agent infers this is the tool to call when it needs a pose converted between frames, but there is no explicit 'use this when' clause, no mention of alternatives, and no note on preconditions such as the frames needing to exist in the ROS graph. Adequate but leaves the selection reasoning to inference.

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