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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuinely non-obvious behavior: the score is decay-weighted, bounded to [0,1], accompanied by a tier, and unknown agents receive a neutral 0.5 prior instead of an error or zero.

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 short sentences, zero waste, with the core purpose and return shape front-loaded. The trailing clause about the 0.5 prior earns its place by foreclosing a common agent assumption about missing data.

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 single-parameter read tool with an output schema, the description covers scoring semantics and the unknown-agent edge case, which is the main ambiguity. The remaining gap is the identifier format and what 'tier' means, both of which an agent could want before calling.

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?

One required parameter (agent_id) with 0% schema description coverage, so the description must carry the burden and only partially does — 'an agent's' implies an identifier but never states whether it is a name, UUID, or DID, or what happens on a malformed value. Baseline is low given the coverage gap.

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?

States a specific verb and resource ('Get an agent's decay-weighted trust score') plus the output shape ('in [0,1] and tier'), which is far more informative than the name alone. It does not explicitly contrast itself with siblings like history or verify_attestation, so an agent must infer that this is the read-only aggregate view.

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 description makes clear you call it to obtain a trust score, but never says when to prefer it over history or describe_agent, nor any preconditions. The second sentence describes edge-case behavior rather than when-to-use guidance.

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