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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered; the description adds real behavioral content by describing the shape of the response (ordered spans with durations and error messages). It says nothing about trace size limits, truncation, or what happens for an unknown or expired trace id.

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, no filler, front-loaded with what the tool returns before the input requirement. Every clause carries information an agent would otherwise have to guess.

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 no output schema, the description carries the return-value burden and does so adequately for a single-trace read tool, covering span ordering, durations and error detail. Missing is any note on large-trace behavior or result truncation, which an agent would want before dumping output.

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 only 50%: the project parameter is documented in the schema, but trace_id has no description there. The description compensates by explaining where a valid trace_id comes from (incidents, logs, database results), which is meaningful guidance the schema does not provide.

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 (read/fetch) and resource (one request trace) and enumerates what the result contains: spans in order, services, database calls, outgoing calls, durations, failures. That distinguishes it from aggregate siblings like relia_dashboard or relia_vitals, though it never names the closest alternatives (relia_logs, relia_session) explicitly.

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?

"Takes a trace id as found in incidents, logs or database results" gives a concrete precondition and tells the agent where to source the id before calling. It stops short of stating when NOT to use it (e.g. when you have only a session or a log search in mind and should use relia_session or relia_logs instead).

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