get_pileup

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

The description discloses a critical behavioral trait: the tool is not implemented in this build and returns error code 'unsupported' (E4). This goes beyond the annotations, which only declare readOnlyHint and openWorldHint. The description also clarifies the input requirement (indexed BAM/CRAM), which is useful behavioral context. No contradiction with 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?

The description is two sentences and front-loads the core purpose. The second sentence about the 'unsupported' error is essential and earns its place. No wasted words, though it could have added a bit more parameter context without becoming verbose.

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?

Given the tool is not implemented, the description is arguably complete for the 'unsupported' path. However, for a tool with 8 parameters and 13% schema coverage, the description does not explain the semantics of the filtering parameters (max_depth, exclude_flags, quality thresholds). The output schema exists, so return values are covered, but the parameter semantics gap makes it incomplete for an agent that might need to construct a valid request.

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 only 13%, so the description must compensate for the many undocumented parameters. The description mentions 'indexed BAM/CRAM' and 'interval', which maps to the file and interval parameters, but it does not explain max_depth, exclude_flags, min_base_quality, min_mapping_quality, max_records, or reference. The description adds minimal meaning beyond the schema for the core parameters but leaves most parameters unexplained.

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: 'Per-position base counts over an interval from indexed BAM/CRAM.' This clearly identifies what the tool computes and the input type. It doesn't explicitly differentiate from siblings like get_coverage or get_reads, but the phrase 'per-position base counts' is specific enough to convey the core purpose.

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 implies usage context: it operates on indexed BAM/CRAM files over an interval. However, it does not explicitly state when to use this tool versus alternatives like get_coverage or get_reads, nor does it mention exclusions. The 'Not implemented in this build' note is a form of usage guidance (don't use it expecting success), but it doesn't help an agent choose between siblings.

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