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

Annotations already indicate a mutable (readOnlyHint=false) and idempotent (idempotentHint=true) operation. The description adds the key behavioral constraint that status is not manually changeable, and clarifies that transitions occur via evidence judge verdicts. This goes beyond the annotations and discloses a non-obvious behavior.

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?

Two sentences, front-loaded with the main purpose. The first sentence states exactly what the tool does, and the second adds a critical limitation without redundancy. No filler or repetition of schema content.

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 is simple (3 params, no output schema). The description covers the core update behavior and the key status limitation. Though it doesn't mention that text and signpost are optional (only assumptionId required), the schema already conveys that. Overall, it's 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?

The input schema provides 100% coverage with descriptions for each parameter (e.g., 'New text of assumption', 'New failure indicator', 'UUID of assumption'). The description adds no additional parameter-level nuance, so the baseline 3 applies.

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 specific verb 'Update' and resource 'assumption' with the exact fields 'text or signpost'. This clearly distinguishes it from sibling tools like goal-update (for goals) and goal-update-criterion (for criteria). The additional status constraint clarifies the scope further.

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?

It provides clear context: this tool is for updating assumption text/signpost, not for status changes. The description explicitly states 'Status cannot be changed manually' and points to evidence judge verdicts as the alternative mechanism, though it doesn't name a specific alternative tool. This gives a clear when-not and some alternative guidance.

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