nexus_understand_architecture

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so safety is covered. The description adds real value beyond them by enumerating what the summary covers (counts, formats/types, blob stores, group membership, offline repos) and noting results come "with evidence," which signals citations/backing data rather than bare assertions. It omits any note on cost, latency, or size of the summary, which is the main remaining gap.

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?

A single sentence that leads with the verb and resource, then lists the covered dimensions compactly. Every clause names a distinct piece of content; there is no filler or restatement of the tool name.

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?

With zero parameters, an output schema present, and full annotation coverage, the description only needs to convey scope and placement — and it conveys scope well. The missing piece is placement relative to siblings (inventory JSON, architecture markdown, smell detection), which is the one thing an agent still has to guess.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a no-parameter tool applies. Nothing in the text misleads about inputs.

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?

Specific verb ("Summarize") plus a specific resource ("the instance") and an enumerated scope: object counts, repositories by format/type, blob store usage, group membership, offline repositories. An agent can tell this is a broad inventory/overview read. It does not, however, distinguish itself from close siblings such as nexus_generate_inventory_json or nexus_generate_architecture_md, which appear to cover overlapping 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 word "Summarize" — this is the high-level overview call — but there is no explicit when-to-use statement, no when-not, and no named alternative among the eleven siblings. The agent must infer that this is the entry point before drilling into nexus_explain_repository or nexus_generate_architecture_md.

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