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's job is to add context — and it does: the payload is generated from the same registry the tools come from, so the server cannot serve a stale copy, but the client's cached connector tool list can. It then supplies the remediation (remove/re-add the connector, start a new chat). That is genuinely useful operational detail no annotation or schema conveys.

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 what the tool returns before the operational advice, and most sentences carry distinct information. It is slightly padded — 'This schema is the truth; the tool list is a cache of it' restates the caching point already made two sentences earlier, and the connector-cache warning runs long for a zero-arg tool.

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?

No output schema exists, but the description enumerates the payload's contents (modules, entities, lifecycles, rules, commands), states its freshness guarantee and its failure mode, and tells the agent what to do if reality diverges. For a zero-parameter read tool, an agent has everything needed to call it and interpret the result.

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 and the schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies; the description correctly spends no words on nonexistent arguments.

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 concrete verb-and-content pair: it returns the system's shape — modules, entities, lifecycles, encoded rules, and every command. That is instantly distinguishable from every sibling, which are all specific operational tools, and an agent can tell this is the introspection/meta entry point without opening anything.

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?

Gives an explicit, prescriptive trigger: 'Call this first in a new session', plus the rationale ('cheaper than guessing') and a diagnostic path if a listed command is absent from the tool list. It stops short of naming when NOT to call it or a sibling alternative (e.g. core_spec_status, core_next_actions), which keeps it off a 5.

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