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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds critical non-obvious behavior: it performs a read-modify-write because Arcoro replaces the job on PUT, and concurrent edits to the same job can silently overwrite each other, so edits must be serialized. That is exactly the operational context an agent cannot infer from annotations.

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?

Three sentences, front-loaded with the operation type and the endpoint at the end. Every clause carries distinct information (what changes, how partial updates work, race-condition warning) with no repetition of schema fields.

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 an 11-parameter mutation tool with no output schema, the description covers the mutation model, null semantics, and concurrency risk, which is enough to call it safely. It stops short of mentioning permission requirements or confirming the response shape, leaving a minor gap.

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 the baseline is 3, but the description adds meaning beyond the schema: only supplied fields are mutated, null clears nullable fields, and setting location_ids turns off 'available at all locations'. That partial-update framing changes how an agent should reason about the 11 parameters.

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?

Opens with an explicit 'WRITE' marker, a specific verb ('change fields of an existing job') and concrete examples (rename, set dates, assign locations, close via is_active=false). An agent can immediately distinguish this from exaktime_create_job or exaktime_update_location.

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 clear conditions for use: partial update semantics ('Only the fields you pass change'), how to close a job (is_active=false), and how to clear a nullable field (null). It does not explicitly name sibling alternatives, but the guidance for when and how to apply this mutation is unambiguous.

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