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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so safety is fully covered. The description adds one genuinely new behavioral fact — that this endpoint is not in the public credit manifest, so pricing must come from the plan — which is useful for cost-sensitive agents, but it says nothing about result size or depth of the symbol corpus.

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 prose sentence followed by four bracketed metadata tags — group, endpoint, required param, cost. Nothing is padded, and the operative fact (what is indexed by what) is front-loaded.

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 an output schema present, the description need not describe return values; annotations cover the safety profile and the schema covers all three parameters. The only real gap is the absence of sibling routing, which keeps it out of the top band for a tool in a very crowded namespace.

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% and the element enum is fully documented, so the schema carries the parameter burden. The description only repeats the enum values and adds no semantics about what 'spirit' contains versus the four classical elements, or about how fields/precision interact with this response.

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 resource and indexing dimension: dream symbols grouped by element, with the five valid groupings enumerated. An agent can tell this is a lookup/list tool rather than a decoder, but the description never contrasts it with nearby siblings like dreams_symbol_keyword, dreams_decode, or dreams_recurring_themes.

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?

There is no when-to-use guidance at all. "[Required: element]" merely restates the schema's required field and does not explain when an agent should browse by element versus looking up a single symbol keyword or decoding a full dream.

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