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

With no annotations, the description must carry the behavior burden. It does convey that this is a read-only operation over public Markdown and that matching is approximate ('関係しそうな' - likely related) rather than exact, which is genuinely useful. It omits result limits, whether snippets or full documents are returned, and how multiple keywords or phrases are handled.

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?

Two short sentences, front-loaded with the operation and resource, followed by a useful scoping note that this is the simple keyword variant. No filler.

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?

For a one-parameter search tool with no output schema, the agent needs to know roughly what comes back. The description says related body text is returned but not how much, in what form (snippet vs. whole document), or with what metadata, leaving a meaningful gap.

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 coverage is 0% and the single parameter has no description, so the description must compensate. 'queryに関係しそうな本文' establishes that query is a relevance-bearing search string, but adds no detail on tokenization, multiple keywords, phrase syntax, or operators.

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: reads across TubeSaku's public Markdown and returns body text relevant to the query. It also signals this is the 'simple keyword search version', hinting at a tier relative to other retrieval tools, but it never names a sibling such as read_tubesaku_markdown or get_tubesaku_index, so differentiation is left to inference.

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 phrase 'まずは単純なキーワード検索版' implies this is the entry-level retrieval option, which is a usable usage cue. However, there is no explicit when-to-use/when-not guidance and no mention of when to prefer the sibling read or index tools, so the agent must guess at routing.

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