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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds useful behavioral context: results are capped at 8, reflect only the last run, and each row is dated and attributed. It does not explain what happens if there is no last run or whether results are stable.

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?

The description is three short sentences and front-loads the core behavior. The final sentence about the REST endpoint is useful routing information, though slightly promotional; nothing is verbose or buried.

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 simple read-only sample tool with no output schema, the description is adequate but incomplete. It explains the sample size and row properties, but leaves the required 'source_id' parameter and edge-case behavior undocumented.

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 only 50%, and the description does not compensate for the undocumented 'source_id' parameter. It restates the 8-row limit already present in the schema but adds no meaning about required source identification or how 'source_id' is obtained.

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 action and resource: sampling up to 8 rows from the last run of a source. It is clearer than the terse name 'get_rows' and distinguishes itself from 'get_source' or 'list_sources' by focusing on rows, but it does not explicitly contrast with any sibling.

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 phrase 'up to 8 sample rows from the last run' implies a preview/sample use case, and the REST endpoint note points to an alternative for more data. However, it does not say when to prefer this over 'get_source', 'source_report', or other source-related siblings.

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