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

Annotations already declare readOnly=false, idempotent=true, destructive=false, and closed-world, so the description need not restate safety. It usefully adds hard limits (65536 request bytes, 5 s execution) and the 'software/model evidence only' scope, but omits that this is a priced buyer job (schema carries max_total_price and idempotency_key), which is meaningful behavioral context an agent needing cost awareness would want.

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 Problem/Input/Result/Limits skeleton is tightly front-loaded and every clause carries information. Slightly dense and telegraphic, but no filler sentences.

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?

Output schema exists, so return values need not be spelled out, and the description still summarizes them well. However, for a paid, idempotent job-submission tool with a fully undocumented nested request schema, the definition omits pricing/cost behavior and job lifecycle details that materially affect correct invocation.

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% across 4 required params, and the schema is an opaque nested anyOf object, so the description carries real burden. It adds meaningful content by naming the payload parts ('observations, model, rules'), partially compensating for the undocumented 'request' object, but says nothing about schema_version, idempotency_key, or max_total_price.

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 names a specific verb and resource ('Fuse ... synchronized sensor observations') and scopes it to a bounded observation set under 'the supplied diagonal uncertainty model and rules.' It is clear what the tool does, but it does not distinguish itself from close siblings like robotics_compare_state_estimators or robotics_validate_closed_loop_stability, which also consume sensor/state inputs.

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?

There is no guidance on when to choose this over alternatives, no prerequisites, and no exclusions. The 'Problem:' framing implies the scenario but never states the conditions that select this estimator over a competing one among the ~20 robotics siblings.

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