Open nixpkgs issues

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuine context beyond them: the data is a PR digest refreshed hourly, and it explains the meaning of the derived hydra:/update: fields and their value sets. It stops short of describing return format or pagination behavior.

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 sentences, with the core purpose front-loaded before the per-kind detail. The second sentence is dense and its grammar is awkward ('what Hydra builds now say'), but no sentence is wasted.

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, open-world search tool with all five parameters fully documented in the schema and no output schema, the description supplies the missing conceptual layer: what the two issue kinds carry and how the derived fields should be read. The main gap is the absence of any routing guidance relative to the overlapping siblings.

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 every one of the five parameters (kind, limit, search, package, verdict) is already documented with enums spelled out. The description's mention of 'builds: ... failing; waiting' partially overlaps the verdict enum but adds no format or syntax detail beyond the schema. Baseline 3 applies.

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: 'Search nixpkgs' open issues by title', with the data source (the PR digest) identified. It splits the resource into two kinds (build-failure vs update requests), which is descriptive, but it never distinguishes itself from the sibling tools build_failures and update_attempts that appear to cover the same ground.

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?

Usage is implied by the description of what each issue kind contains and the note that the digest is hourly, but there is no explicit statement of when to choose this tool over build_failures or update_attempts, and no prerequisites or exclusions. No guidance on the limit/search interplay either.

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