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

The annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile needs no restating. The description adds the useful behavioral detail that data is bucketed every 15 minutes and includes the starting value. It is silent on pagination behavior even though limit and cursor exist, and on how large the result set can get.

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?

One sentence, front-loaded with the resource and the sampling interval, then the prerequisite. Nothing is wasted, though the trailing clause about the starting value is slightly compressed and could read more clearly.

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 read-only, four-parameter time-series call with no output schema, the description covers the grain of the data but not the response shape, max row count, or how pagination interacts with the 200-row default. It is adequate to call the tool correctly but not to predict what comes back.

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 75%, with limit and cursor fully documented and user_request explained in depth, so the baseline is 3. The description adds genuine meaning only for id by naming get_projections as its source, which is the one gap the schema leaves open.

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?

The description states a specific verb and resource: it returns the reported pick count for a single line at 15-minute intervals, plus the starting value. An agent can tell it is a time-series read for one line rather than a comparison or a history dump. It does not distinguish itself from the similar sibling get_line_history, which leaves some ambiguity.

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?

It gives a prerequisite pointer: 'Use an id from get_projections,' which directly tells the agent where the required id comes from. It says nothing about when to choose this tool over get_line_history or compare_lines, so the agent must infer the boundary.

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