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

Annotations already declare destructiveHint=true and readOnlyHint=false; the description neither contradicts this nor explains what is actually destroyed (e.g., whether omitted fields are preserved or wiped). The check-first advice and the "patch and/or themeInput" framing hint at partial-vs-full replacement semantics, which is genuinely beyond the annotations, but merge behavior remains unspecified for a destructive write.

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, the mutation described first and the prerequisite second. No filler and nothing repeated from the schema.

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?

A destructive, non-read-only mutation with no output schema needs to spell out what is overwritten; the description only implies it. The safety hint covers part of the gap, but an agent still cannot predict the effect of supplying only patch or both payloads.

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 100%, so all four parameters are already documented in structured fields. The description's "(patch and/or themeInput)" adds the useful signal that either or both may be supplied, but contributes nothing about merge vs overwrite semantics or the shape of the accepted objects.

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 ("Update a theme") and enumerates the two payload parameters, so the operation is unambiguous. However, it does not distinguish itself from report_theme_create or report_theme_delete in the sibling list, so the agent must infer that this is the mutation-of-existing path.

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?

"Use report_theme_get to check current values first" gives an explicit precondition and names the alternative read tool, which is real routing guidance. It stops short of saying when to prefer this over create/delete or what happens if the theme id is invalid.

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