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

Annotations already declare destructiveHint=true, so the mutation risk is partly covered by structured data. The description reinforces this with 'MODIFIES live monitoring config' and adds the partial-update contract and the timeout/schedule exclusivity rule, but discloses nothing about permissions, failure modes, or what happens to omitted fields. It adds some value over the annotation without being rich.

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?

Four tight clauses, front-loaded with the verb and the risk, then the partial-update rule, then the exclusivity caveat and return statement. Every clause carries information, though the em-dash-dense single sentence is slightly harder to scan than a short multi-sentence form.

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 13-parameter mutation tool with no output schema, the description covers the mutation semantics, the partial-update contract, and the return value ('Returns the updated check'). The main remaining gap is that fields like 'unique' and 'channels' behave differently on update than on create, which is not addressed.

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 100%, so all 13 parameters are already documented, including the timeout/schedule mutual-exclusion rule and the tz dependency. The description merely restates the exclusivity constraint rather than adding syntax, defaults, or format guidance beyond the schema. 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?

States a specific verb (UPDATES), a specific resource (an existing check) and the addressing key (by UUID), plus the consequence ('MODIFIES live monitoring config'). The sibling set is cleanly partitioned into create/delete/get/pause/resume, and this description makes clear it is the in-place mutation 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?

Gives actionable usage guidance: send only the fields you want to change (partial update), and flags that timeout and schedule remain mutually exclusive. It stops short of explicitly naming alternatives such as create_check for new checks or pause_check for state changes, so it earns a 4 rather than a 5.

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