List HACS repositories

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and network scope are covered structurally. The description adds genuine behavioral context by defining the population returned (custom + fetched default-store repos) and the per-row shape, though it says nothing about result size limits or pagination.

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, both earning their place: the first defines scope and output, the second gives the call-time routing condition. Nothing redundant and the most decision-relevant content leads.

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?

There is no output schema, so the description usefully enumerates the returned fields, and it covers both the data scope and the reason to call it. It is nearly complete; only a note on result volume or ordering is missing for a list tool.

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%, with both 'categories' and 'instance_id' fully documented, including the refusal behavior for a mismatched instance. The description adds nothing about either parameter, so the baseline 3 applies — it neither compensates for nor detracts from the schema.

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 ('List repositories HACS knows about') and pins down the exact scope — custom plus default-store entries that have fetched metadata. It further enumerates the returned row fields (id, full_name, category, installed, custom), so an agent knows precisely what it gets and how it differs from ha_hacs_info.

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?

Explicitly states the operative use case: 'Use this to find a repository's id before calling ha_hacs_download_repository or ha_hacs_remove_repository.' That names the downstream siblings and the condition that selects this tool, turning it into a routing rule rather than a bare description.

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