Complete a task

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

With no annotations, the description carries the full behavioral burden. It usefully discloses a side effect beyond the obvious one ('Stamps today's date'), but says nothing about whether completion is reversible, what happens on an ambiguous fragment, or what is returned on success.

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, no filler, with the action and accepted inputs front-loaded and the side effect stated last. Every clause earns its place.

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 mutation tool with no output schema and no annotations, the description covers both input modes and one non-obvious side effect. It is only short on error/ambiguity behavior, which is a modest gap at this complexity.

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 already 100%, so the baseline is 3. The description goes beyond the schema by explaining the provenance of the id ('from list_tasks') and that the free-text form must be a unique fragment, which adds real matching semantics.

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 ('Mark a task done') and names the two accepted identifiers, so an agent knows exactly what the tool does. It does not differentiate itself from the sibling update_task, which could plausibly also set completion state, so it falls short of a 5.

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?

The description tells the agent where task ids come from ('from list_tasks') and that a text fragment is an accepted alternative, which is implied usage guidance. It never states when to prefer this tool over update_task or what to do if the fragment is not unique.

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