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

The description adds valuable behavioral context beyond the annotations: it states that adding an article does not change its publication status or URL, and that inserting at a position shifts later articles down. It also notes that errors occur if either slug is unknown. The annotations already indicate readOnlyHint=false, openWorldHint=true, idempotentHint=true, and destructiveHint=false, and the description aligns with these without contradicting them. It could have mentioned idempotency explicitly, but the annotations cover that.

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?

The description is concise and well-structured. It starts with a clear one-sentence summary, then provides necessary details in a logical order: prerequisites, identification method, optional parameter behavior, and side effects. Every sentence adds value without redundancy. It is front-loaded with the core purpose and then elaborates.

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?

Given the tool's moderate complexity (3 parameters, no output schema), the description is complete. It covers prerequisites, parameter semantics, side effects, and error conditions. The annotations provide additional safety hints, and the schema covers parameter details. There is no missing information that would prevent an agent from using the tool 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?

The schema already has 100% coverage with detailed descriptions for each parameter, including the 1-based position and the source of slugs. The description reinforces this by explaining the position behavior and the need to use slugs from specific tools. It adds a bit of extra context (e.g., 'Not its title or id') but mostly complements the schema. Since the schema is thorough, the description's additional value is moderate, hence a 4.

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?

The description clearly states the tool's function: 'Place an existing article into an existing series, optionally at a specific position.' It specifies the verb (place/add), the resources (article, series), and the key constraint (both must already exist). It also distinguishes from siblings like create_series and update_article by emphasizing it does not create either entity.

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 description provides explicit guidance on when to use this tool: it requires both the series and article to already exist, and it directs the user to get slugs from get_series and article tools. It also explains the optional position parameter and the behavior of omitting it (append at end). This clearly differentiates it from creation tools and provides context for when it is appropriate.

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