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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description earns credit for the operational context they cannot carry: a hard 100,000-character response cap that refuses oversized replies and reports the size, plus loader-issue reporting including shadowed names. It also discloses what the default summary deliberately omits (schema, parameters, view extensions, semantics, tokens, metadata) and which draft fields are never snapshot outputs.

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?

Front-loaded with the core purpose, then progressively narrower conditionals and finally sibling routing; every sentence carries information with no filler. The telegraphic fragment style ("detail full includes definitions; names narrows them") is dense but occasionally clipped enough to require a second read.

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 no output schema, the description carries the full burden of describing return values, and it does: the summary field list, the loader-issue report, the etag/generatedAt pair, the size-refusal response, and the hiddenInternal count. Combined with complete parameter documentation and sibling routing, an agent has everything needed to call it correctly.

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 the baseline is 3, but the description adds meaning beyond the schema: it explains that detail full returns definitions and is most useful combined with names, that names narrows the result set (with misses surfacing in notFound per the schema), and that includeInternal appends internal objects after business ones.

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 ("Read the registry summary") and enumerates what comes back: active objects and traits, loaded names, loader issues, etag and generatedAt. It explicitly differentiates from siblings by noting that object_registry reads one composed object and catalog_list reads components, so an agent can select it without opening a schema.

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 closing sentence routes the agent to alternatives by describing what each sibling does (object_registry for a single composed object, catalog_list for components), which implies when not to use this tool. It also states the detail/names conditionals that select between summary and full output, though it never phrases an explicit "use X instead when..." exclusion.

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