project-open

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds minimal behavioral context: it implies the tool reads a file and produces a summary, but doesn't specify whether it writes to the project state or just reads. Given the annotations cover safety, this is acceptable but not enriched; the description adds only the file-type detail.

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 a single sentence, concise and front-loaded with the verb and resource. It is under the typical length, which is acceptable for a simple tool. However, it could be more structured by separating the summary details, but it's not verbose. It earns a 4.

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 a single parameter fully described in the schema and rich annotations covering safety, the description is mostly complete for understanding what the tool does. However, it lacks what 'summarize' returns (output) and how it relates to sibling tools. Since there is no output schema, the description should describe the return format, but it doesn't. This gap lowers the completeness.

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%, so the schema fully documents the 'path' parameter. The description does not repeat parameter details, which is fine. Since there is only one parameter and it's well-described in the schema, the description adds no new meaning but also doesn't need to. Baseline of 4 is appropriate.

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 states a clear verb ('Open') and resource ('.mblock/.sb3') but the purpose is vague about what 'summarize' entails. There are many sibling tools (list_targets, list_blocks, get_block) that might handle specific summarization, but this tool's unique role is not explicit. The term 'summarize' could mean many things, and it doesn't clarify its scope relative to siblings.

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 gives no guidance on when to use this tool versus alternatives like project-validate, project-list, or list_targets. It doesn't state prerequisites (e.g., project must be attached or created first) or when to avoid it. An agent could confuse this with project-validate or project-list, and there's no hint to disambiguate.

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