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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's key contribution is behavioral: no cross-language fallback, missing keys surface in `missing` rather than `texts`, and a direct instruction not to invent/translate replacements. This is real context beyond the structured fields, though it does not cover cost tiers or batching limits in the description body.

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?

Purpose and key grammar are front-loaded, which is good, but the text is marred by a truncated fragment ('Planet in…') and by stating the `missing`-vs-`texts` behavior twice (once inline, once in the trailing paragraph). The redundancy consumes space without adding information.

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?

An output schema exists, so return values need not be explained. For a four-parameter tool the description covers the required params, their formats, and the important edge case of unavailable texts, leaving only the compact-mode params (covered by the schema) undocumented in prose.

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%, including the full key grammar and enum for `lang`, so the schema already carries the parameter semantics. The description restates the key examples rather than extending them, which meets the baseline but adds no new meaning; `fields` and `precision` appear only in 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 ('Edited interpretation texts for a chart') and adds a genuine differentiator: 'no AI at request time,' which separates it from AI-driven siblings like astroway_mcp_ai_explain_aspect. It does not name a specific sibling to contrast against, but the static/AI distinction lets an agent route it correctly.

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 rather than stated: the static, deterministic nature of the texts vs. AI tools is gestured at, and the `missing` semantics are explained, but there is no explicit when-to-use/when-not framework or named alternative. The agent can infer intent but must reason about it.

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